<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>PHP 5 常量_w3cschool</title>
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
    <meta name="renderer" content="webkit" />
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <meta name="keywords" content="PHP 5 常量" />
    <meta name="description" content="PHP 5 常量

常量值被定义后，在脚本的其他任何地方都不能被改变。

 PHP 常量
常量是一个简单值的标识符。该值在脚本中不能改变。
一个常量由英文字母、下划线、和数字组成,但数字不能作为首字母出现。 (常量名不需要加 $ 修饰符)。
注意： 常量在整个脚本中都可以使用。

 设置 PH_来自PHP教程，w3cschool。" />
    <link href="//www.w3cschool.cn/statics/plugins/font-awesome/css/font-awesome.min.css" rel="stylesheet" type="text/css"/>
    <link rel="stylesheet" href="//www.w3cschool.cn/statics/css/w3.css" />
    <link rel="stylesheet" href="//www.w3cschool.cn/statics/css/style-kn-project-view.css" type="text/css" />
    <link rel="stylesheet" href="//www.w3cschool.cn/statics/css/style-theme.css" type="text/css" />
    <link rel="stylesheet" href="//www.w3cschool.cn/statics/css/project.css" />
    <link href="//www.w3cschool.cn/plugins/highlight/styles/default.css" rel="stylesheet" type="text/css"/>
    <script src="//www.w3cschool.cn/plugins/highlight/highlight.pack.js" type="text/javascript"></script>
    <link rel="shortcut icon" href="//www.w3cschool.cn/statics/images/favicon.ico"/>
    <script src="//www.w3cschool.cn/statics/js/jquery-1.8.3.min.js" type="text/javascript"></script>
    <script src="//www.w3cschool.cn/statics/plugins/jquery-slimscroll/jquery.slimscroll.min.js" type="text/javascript"></script>
    <script src="//www.w3cschool.cn/statics/js/project.leftbox.js?v1.1" type="text/javascript"></script>
</head>
<body>
<div id="full-height-container" class="project-container color-theme-white">
    <!--header start-->
    <div id="header">
        <div id="header_item">
            <div id="header_index">
                <div id="header-l">
                    <a href="//www.w3cschool.cn" title="w3cschool" class="logo"><img src="//7nsts.w3cschool.cn/images/w3c/header-logo.png" alt="W3Cschool" /></a>
                    <ul class="header-menu">
                        <li><a href="//www.w3cschool.cn/tutorial" title="编程入门教程">编程入门教程</a></li>
                        <li><a href="//www.w3cschool.cn/minicourse/" title="编程微课">编程微课</a></li>
                        <li><a href="//www.w3cschool.cn/manual" title="开源技术文档">极客文档</a></li>
                        <li class="dropdown"><a href="#" class="dropbtn">学院<i class="down-icon1 angle-down-icon"></i></a>
                            <div class="dropdown-content">
                                <a href="//www.w3cschool.cn/codecamp/" title="编程实战训练">编程实战训练</a>
                                <a href="//www.w3cschool.cn/examples" title="编程实例">编程实例</a>
                                <a href="//www.w3cschool.cn/exam/" title="编程题库">编程题库</a>
                                <a href="//www.w3cschool.cn/question/" title="编程问答">编程问答</a>
                                <a href="//www.w3cschool.cn/codedemo" title="代码实例">代码实例</a>
                            </div>
                        </li>
                        <li class="dropdown"><a href="#" class="dropbtn">百宝箱<i class="down-icon1 angle-down-icon"></i></a>
                            <div class="dropdown-content">
                                <a href="//123.w3cschool.cn/webtools" target="_blank" title="W3Cschool在线工具集合">在线工具</a>
                                <a href="//123.w3cschool.cn" target="_blank" title="W3Cschool极客导航">极客导航</a>
                                <a href="//www.w3cschool.cn/dict/" title="速查词典">速查词典</a>
                                <a href="//www.w3cschool.cn/group/" title="群组">群组</a>
                                <a href="//www.w3cschool.cn/position/positionlist" title="职位进阶">职位进阶</a>
                                <a href="//www.w3cschool.cn/popularuser" title="排行榜">排行榜</a>
                                <a href="//www.w3cschool.cn/activity/" title="活动">活动</a>
                            </div>
                        </li>
                        <li><a href="//www.w3cschool.cn/vip" title="会员">会员<i class="hot-icon"></i></a></li>
                    </ul>
                </div>
                <div id="header-r">
                    <div class="sig-box" >
                        <a href="/register?refer=/" rel="nofollow">注册</a><!-- href="/register?refer=/" --> |
                        <a href="/login?refer=/" rel="nofollow">登录</a>
                    </div>
                    <a href="//www.w3cschool.cn/download" target="_blank" class="header-app" title="w3cschool移动端">移动端
                        <div class="dropdown-content qrcode-box">
                            <span class="j"></span>
                            <div class="qrcode-img">
                                <img src="//7nsts.w3cschool.cn/images/w3c/app-qrcode2.png" alt="扫码下载APP" width="150" height="150">
                                <p>扫码下载APP</p>
                            </div>
                            <div class="qrcode-img">
                                <img src="//7nsts.w3cschool.cn/images/w3c/w3cschool.png" alt="w3cschool公众号" width="150" height="150">
                                <p>w3cschool公众号</p>
                            </div>
                        </div>
                    </a>
                    <div class="searchbox">
                        <form action="/search" target="_self">
                            <input type="text" name="w" class="box" id="searched_content" placeholder="输入关键字搜索..."/>
                            <button type="submit" class="button"/></button>
                        </form>
                    </div>
                </div>
            </div>
        </div>
    </div>
    <div class="register-Box" id="register-Box" style="display: none;">
        <div class="register-Box-content">
            <div class="register-Box-top">
                <span class="register-Box-title">注册成功</span>
                <span onclick="closeDialogBox(this)" class="feedback-Box-close">X</span>
            </div>
            <div class="register-Box-info">
                <div class="register-Box-left" style="float: left;">
                    <img class="register-cover" src="//7n.w3cschool.cn/attachments/avatar2/avatar_14.jpg">
                </div>
                <div class="register-Box-right">

                    <p class="register-userinfo-title">
                        <i class="usertype-ico-1"></i><span>W3Cschool</span>
                    </p>
                    <p class="register-userinfo-info">恭喜您成为首批注册用户</p>
                    <p class="register-userinfo-info">获得88经验值奖励</p>
                    <button class="search-s" onclick="closeDialogBox(this)" id="registerSubmit">马上体验</button>
                </div>
            </div>
        </div>
    </div>
    <script>
        var apppath = '/php/php-constants.html';
        var domain  = '//www.w3cschool.cn';
    </script>
    <!--header end-->
    <div id="m-splitter">
        <div class="m-splitter-left left-container">
            <div class="fixed-sidebar mscroller" style="width:100%;">
                <div class="splitter-sidebar">
                    <div class="sidebar-space-info">
                        <a href="/php" title="PHP教程">
                            <div class="sidebar-pro-wrapper">
                                <div class="sidebar-pro-container">
                                    <div class="sidebar-pro-img">
                                        <span><img class="pimg-cover" alt="PHP教程" src="/attachments/cover/cover_php.png"></span>
                                    </div>
                                </div>
                            </div>
                            <div class="pro-name-container">
                                <div class="sidebar-pro-name">
                                    <span>PHP教程</span>
                                </div>
                            </div>
                        </a>
                    </div>
                    <div class="sidebar-pro-nav">
                        <ul class="page-sidebar-menu">
                            <li class="pro-m">
                                <a class="btn-thumbs-up" href="javascript:;" onclick="isProjectLike()" >
                                    <i class="icon-thumbs-up"></i> <span id="plikestatus">赞</span>
                                </a>
                            </li>
                            <li class="pro-m">
                                <a id="hbstar" href="javascript:;" onclick="isProjectStar()" data-type="star"><i class="icon-star"></i> <span>收藏</span></a>
                            </li>
                            <li class="pro-m">
                                <a href="javascript:;" title="分享" class="share-btn  popup_more bdsharebuttonbox" data-cmd="more" data-bd-bind="1472196006351"><i class="icon-share"></i> 分享</a>
                            </li>
                        </ul>
                    </div>
                    <div class="sidebar-menu">
                        <ul>
                            <li class="nav-item"><a href="/php/list/" title="wiki列表"><i class="icon-bookmark-empty"></i> <span class="nav-item-label">Wiki列表</span></a></li>
                            <li class="nav-item"><a href="/php/topic" target="_blank" title="php问答讨论区"><i class="icon-question-sign"></i> <span class="nav-item-label">php问答讨论区</span></a></li></ul>
                    </div>
                    <!--左侧栏导航 start-->
                    <div class="sidebar-nav">
                        <ul class="treeth">
                            <li class="active" target="sidebar-tree-content"><a href="javascript:;" class="text" title="目录"><i class="icon icon-th-list"></i> <span class="title">目录</span></a></li>
                            <li class="" target="search-box"><a href="javascript:;" class="text" title="搜索"><i class="icon icon-search"></i> <span class="title">搜索</span></a></li>
                            <li target="stars-box"><a href="javascript:;" class="text" title="收藏"><i class="icon icon-heart"></i> <span class="title">收藏</span></a></li>
                        </ul>
                    </div>
                    <!--左侧栏导航 end-->
                    <div style="clear:both"></div>
                    <div class="sidebar-content">
                        <div class="sidebar-tree">
                            <div class="sidebar-tree-content">
                                <div class="dd" id="nestable_handbook" data-tid="4546" data-id="handbook">
                                    <ol class="dd-list">



                                        <li class="dd-item" data-id="kdl3ef21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 教程">PHP 教程</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-tutorial" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 是什么">PHP 是什么</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-intro" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 简介">PHP 简介</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-install" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 安装">PHP 安装</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-syntax" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 语法">PHP 语法</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-variables" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 变量">PHP 变量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-echo-print" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP echo和print 语句">PHP echo和print 语句</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-datatypes" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 数据类型">PHP 5 数据类型</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-constants" ismenu="0" ktype="kn">
                                                    <div class="dd-content   active ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 常量">PHP 5 常量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-string" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 字符串变量">PHP 字符串变量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-operators" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 运算符">PHP 运算符</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-if-else" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP if...else 语句">PHP if...else 语句</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-switch" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP switch 语句">PHP switch 语句</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-arrays" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 数组">PHP 数组</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-arrays-sort" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 数组排序">PHP 数组排序</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-superglobals" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 超级全局变量">PHP 超级全局变量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-looping" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP while 循环">PHP while 循环</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-looping-for" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP for 循环">PHP for 循环</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-functions" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 函数">PHP 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="ep982fkz" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 魔术常量">PHP 魔术常量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="b298tfl0" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 命名空间">PHP 命名空间</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-oop" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 面向对象">PHP 面向对象</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="p7cz5f21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 表单">PHP 表单</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-forms" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 表单">PHP 表单</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="fnrqtfl1" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 表单验证">PHP 表单验证</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="xwyjlfl2" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 表单 - 必需字段">PHP 表单 - 必需字段</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="ijxl7fl4" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 表单 - 验证邮件和URL">PHP 表单 - 验证邮件和URL</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="7t2befl5" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 完整表单实例">PHP 完整表单实例</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-get" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP $_GET 变量">PHP $_GET 变量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-post" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP $_POST 变量">PHP $_POST 变量</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="goriyf21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 高级教程">PHP 高级教程</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-arrays-multi" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 多维数组">PHP 多维数组</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-date" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 日期">PHP 日期</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="func-date-date" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP date() 函数">PHP date() 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-includes" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 包含">PHP 包含</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-file" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 文件">PHP 文件</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-file-upload" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 文件上传">PHP 文件上传</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-cookies" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Cookies">PHP Cookies</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-sessions" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Sessions">PHP Sessions</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mail" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP E-Mail">PHP E-Mail</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-secure-mail" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 安全 E-mail">PHP 安全 E-mail</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-error" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 错误处理">PHP 错误处理</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-exception" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 异常处理">PHP 异常处理</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-filter" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 过滤器">PHP 过滤器</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="ar6jqfl6" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 高级过滤器">PHP 高级过滤器</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-json" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP JSON">PHP JSON</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="u6zv9f21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 数据库">PHP 数据库</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-mysql-intro" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 简介">PHP MySQL 简介</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-connect" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 连接 MySQL">PHP 连接 MySQL</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-create" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 创建数据库">PHP MySQL 创建数据库</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="t16cufl7" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 创建数据表">PHP MySQL 创建数据表</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-insert" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 插入数据">PHP MySQL 插入数据</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-insert-multiple" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 插入多条数据">PHP MySQL 插入多条数据</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-prepared-statements" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 预处理语句">PHP MySQL 预处理语句</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-select" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL 读取数据">PHP MySQL 读取数据</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-where" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL Where 子句">PHP MySQL Where 子句</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-order-by" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL Order By 关键词">PHP MySQL Order By 关键词</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-update" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL Update">PHP MySQL Update</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-mysql-delete" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP MySQL Delete From">PHP MySQL Delete From</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-db-odbc" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 数据库 ODBC">PHP 数据库 ODBC</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="7swk1f21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP XML">PHP XML</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-xml-parser-expat" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP XML Expat 解析器">PHP XML Expat 解析器</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-xml-dom" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP XML DOM">PHP XML DOM</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-xml-simplexml" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP XML SimpleXML">PHP XML SimpleXML</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="4qd8lf21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 与 AJAX">PHP 与 AJAX</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="5idasfl8" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP AJAX 简介">PHP AJAX 简介</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ajax-php" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP – AJAX 与 PHP">PHP – AJAX 与 PHP</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ajax-database" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 实例 AJAX 与 MySQL">PHP 实例 AJAX 与 MySQL</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ajax-xml" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 实例 AJAX 与 XML">PHP 实例 AJAX 与 XML</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ajax-livesearch" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 实例 AJAX 实时搜索">PHP 实例 AJAX 实时搜索</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ajax-rss-reader" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 实例 AJAX RSS 阅读器">PHP 实例 AJAX RSS 阅读器</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ajax-poll" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 实例 AJAX 投票">PHP 实例 AJAX 投票</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="ije2hf21" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 参考手册">PHP 参考手册</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-ref-array" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Array 函数">PHP 5 Array 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-calendar" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Calendar 函数">PHP 5 Calendar 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="dsk69fl9" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP cURL 函数">PHP cURL 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-date" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Date/Time 函数">PHP 5 Date/Time 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-directory" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Directory 函数">PHP 5 Directory 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-error" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Error 和 Logging 函数">PHP Error 和 Logging 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-filesystem" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Filesystem 函数">PHP 5 Filesystem 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-filter" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Filter 函数">PHP Filter 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-ftp" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP FTP 函数">PHP FTP 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-http" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP HTTP 函数">PHP HTTP 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-libxml" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Libxml 函数">PHP Libxml 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-mail" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Mail 函数">PHP Mail 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-math" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Math 函数">PHP 5 Math 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-misc" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Misc. 函数">PHP Misc. 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-mysqli" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 MySQLi 函数">PHP 5 MySQLi 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-pdo" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP PDO">PHP PDO</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-simplexml" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 SimpleXML 函数">PHP 5 SimpleXML 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-string" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 String 函数">PHP 5 String 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-xml" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP XML 函数">PHP XML 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-zip" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP Zip File 函数">PHP Zip File 函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-ref-timezones" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 5 Timezones">PHP 5 Timezones</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-image-gd" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 图像处理">PHP 图像处理</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-serialize" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 序列化/反序列化的方法函数">PHP 序列化/反序列化函数</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-header" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 常用header头定义">PHP 常用header头定义</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="u5mh128c" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 测验">PHP 测验</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-php_quiz" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP 测验">PHP 测验</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-imagecolorexactalpha" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP imagecolorexactalpha – 取得指定的颜色加透明度的索引值">PHP imagecolorexactalpha – 取得指定的颜色加透明度的索引值</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-imagecolorset" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP imagecolorset &#8211; 给指定调色板索引设定颜色">PHP imagecolorset &#8211; 给指定调色板索引设定颜色</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-imagecolorsforindex" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP imagecolorsforindex &#8211; 取得某索引的颜色">PHP imagecolorsforindex &#8211; 取得某索引的颜色</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-imagecolorexact" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP imagecolorexact &#8211; 取得指定颜色的索引值">PHP imagecolorexact &#8211; 取得指定颜色的索引值</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-imagecolordeallocate" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP imagecolordeallocate &#8211; 取消图像颜色的分配">PHP imagecolordeallocate &#8211; 取消图像颜色的分配</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="php-npmx2dp5" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 相关教程">PHP 相关教程</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-q2ul2dp7" ismenu="0" ktype="klink">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                href="PHP7&nbsp;教程：点击进入"    title="PHP7 教程">PHP7 教程</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li></ol></li>

                                        <li class="dd-item" data-id="se1c1uls" ismenu="1" ktype="floder">
                                            <div class="dd-content folder-open ">
                                                <i class="folder icon-folder-open"></i>
                                                <a
                                                        title="PHP 拓展阅读">PHP 拓展阅读</a>
                                            </div>
                                            <ol class="dd-list">




                                                <li class="dd-item" data-id="php-random" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="php随机数各种知识汇集">php随机数各种知识汇集</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-v63m2mu5" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="Window搭建 Nginx PHP 开发环境">Window搭建 Nginx PHP 开发环境</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-recursion" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="实例助你理解php递归函数原理及调用方法">实例助你理解php递归函数原理及调用方法</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-tool" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="13个功能强大的php开发工具推荐及下载">13个功能强大的php开发工具推荐及下载</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-cms" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHPCMS使用说明及其他CMS开源系统推荐">PHPCMS使用说明及其他CMS开源系统推荐</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-thread" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="通俗易懂的php多线程解决方案">通俗易懂的php多线程解决方案</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-frame" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="超实用的开源php框架选择指导">超实用的开源php框架选择指导</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-rxi22oqv" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="json_decode函数详解">json_decode函数详解</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-z28f2ot8" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="2018PHP面试题精选 你敢来挑战吗">2018PHP面试题精选 你敢来挑战吗</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-fcet2otw" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="php文件怎么打开 四种打开php文件的方法">php文件怎么打开 四种打开php文件的方法</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-lp922oty" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="php分页功能的3种实现方法">php分页功能的3种实现方法</a>
                                                    </div>
                                                    <ol class="dd-list">


                                                    </ol></li>


                                                <li class="dd-item" data-id="php-156c2ovf" ismenu="0" ktype="kn">
                                                    <div class="dd-content  ">
                                                        <i class="ic-folder-open2"></i>
                                                        <a
                                                                title="PHP虚拟主机配置教程">PHP虚拟主机配置教程</a>
                                                    </div>
                                                    <ol class="dd-list">

                                                    </ol></li>
                                            </ol>
                                        </li>
                                    </ol>
                                </div>
                            </div>
                            <!--  sidebar-tree-content end  -->
                            <div class="search-box hide1">
                                <div id="knsearch" class="tab-pane">
                                    <div class="knsearch-input">
                                        <input type="text" placeholder="搜索手册内容" name="w" class="input-s">
                                        <button class="knsearchbtn">搜索</button>
                                        <!--<button class="kncleanbtn">清空</button>-->
                                    </div>
                                    <div class="searchres">
                                    </div>
                                    <div class="sidebar-tree-dict"></div>
                                </div>
                            </div>
                            <div class="stars-box hide1">
                                <div id="kncollect" class="tab-pane">
                                    <ul class="dd-list">
                                        <li class="nostar">还没有收藏</li>
                                    </ul>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
                <!-- <div class="space-tools-section">
                <div class="tools-button">
                <a href="" class="expand-collapse-trigger"></a>
                </div>
                </div> -->
            </div>
        </div>
        <div class="splitter-handle left-drager">
            <div class="left-dragger-c splitter-handle-highlight"></div>
        </div>
        <div id="pro-mian" class="main-container font0" >
            <div class="project-body">
                <div class="portlet-title pro-title">
                    <div class="set-btn-group font-settings pull-left">
                        <a href="javascript:;" class="expand-collapse-trigger" title="折叠/展开"><i class="icon-th-list"></i></a>
                        <a href="javascript:;" class="toggle-dropdown" title="视觉主题设置"><i class="icon-font"></i></a>
                        <div class="set-dropdown-menu docblur" style="display:none;">
                            <div class="dropdown-caret">
                                <span class="caret-outer"></span>
                                <span class="caret-inner"></span>
                            </div>
                            <div class="buttons font-opt">
                                <button class="button size font-reduce" font="reduce">A</button>
                                <button class="button size font-enlarge" font="enlarge">A</button>
                            </div>
                            <div class="buttons bg-color">
                                <button class="button theme" color="color-theme-white" title="日间模式">White</button>
                                <button class="button theme" color="color-theme-sepia" title="护眼模式">Sepia</button>
                                <button class="button theme" color="color-theme-night" title="夜间模式">Night</button>
                            </div>
                        </div>
                    </div>
                    <div class="kn-btn-group pull-right">
                        <span id="content-head-viewcount" class="viewcount-btn"><i class="icon-eye-open"></i> <span>阅读(59.1k)</span></span>
                        <a id="knstar" href="javascript:;" onclick="isstar()" data-type="star" ><i class="icon-star"></i> <span>收藏</span></a>
                        <a class="btn-thumbs-up" href="javascript:;" onclick="islike()"><i class="icon-thumbs-up"></i> <span id="likestatus">赞</span>(<span id="likecount">20</span>)</a>
                        <a href="javascript:;" title="分享" class="share-btn  popup_more bdsharebuttonbox" data-cmd="more" data-bd-bind="1472196006351"><i class="icon-share"></i> 分享</a>
                        <a id="correct" href="/edit/php/php-constants" rel="nofollow"><i class="icon-edit"></i> <span>我要纠错</span></a>
                        <div class="pro-tools">
                            <a class="toggle-dropdown" href="#"><i class="icon-ellipsis-horizontal"></i></a>
                            <ul class="dropdown-menu docblur" style="display: none;">

                                <li><a href="javascript:;" title="收录专题" data-ctype="kn" id="collection"><i class="icon-inbox"></i> 收录专题</a></li>

                            </ul>
                        </div>
                    </div>
                </div>
                <div id="pro-mian-header">
                    <div class="content-top">
                        <h1>PHP 5 常量</h1>
                    </div>
                    <div class="kn-infomation">
                        由&nbsp;<span>youj</span>&nbsp;创建，Carrie 最后一次修改&nbsp;<span>2015-09-09</span>
                    </div>
                </div>
                <div class="content-bg">
                    <div class="content-intro view-box "><h2>PHP 5 <span class="color_h1">常量</span> </h2>
                        <hr>
                        <p class="intro">常量值被定义后，在脚本的其他任何地方都不能被改变。</p>
                        <hr>
                        <h2>PHP 常量</h2>
                        <p>常量是一个简单值的标识符。该值在脚本中不能改变。</p>
                        <p>一个常量由英文字母、下划线、和数字组成,但数字不能作为首字母出现。 (常量名不需要加 $ 修饰符)。</p>
                        <p><strong>注意：</strong> 常量在整个脚本中都可以使用。</p>
                        <hr>
                        <h2>设置 PHP 常量</h2>
                        <p>设置常量，使用 define() 函数，函数语法如下：<span style="background-color: rgb(239, 239, 239); font-family: Consolas, &quot;Courier New&quot;, Courier, monospace; white-space: pre-wrap;">    </span><span style="background-color: rgb(239, 239, 239); font-family: Consolas, &quot;Courier New&quot;, Courier, monospace; white-space: pre-wrap;">    </span></p><div class="code"><div>define(string constant_name, mixed value, case_sensitive = true)</div></div>
                        <p>该函数有三个参数:</p>
                        <ul>
                            <li>constant_name：必选参数，常量名称，即标志符。</li>
                            <li>value：必选参数，常量的值。</li>
                            <li>case_sensitive：可选参数，指定是否大小写敏感，设定为 true 表示不敏感。</li>
                        </ul>
                        <p>以下实例我们创建一个 <strong>区分大小写的常量</strong>, 常量值为 "Welcome to w3cschool.cn!"：</p>
                        <div class="example">
                            <h2 class="example">实例</h2>
                            <div class="example_code notranslate">&lt;?php
                                <br>define("GREETING", "Welcome to w3cschool.cn!");
                                <br>echo GREETING;
                                <br>?&gt;</div>
                            <br><a target="_blank" class="showbtn" showtry="1" href="/tryrun/showphp/demo_constant1">尝试一下 »</a>
                        </div>
                        <p>以下实例我们创建一个 <strong>不区分大小写的常量</strong>, 常量值为 "Welcome to w3cschool.cn!"：</p>
                        <div class="example">
                            <h2 class="example">实例</h2>
                            <div class="example_code notranslate">&lt;?php
                                <br>define("GREETING", "Welcome to w3cschool.cn!", true);
                                <br>echo greeting;
                                <br>?&gt;</div>
                            <br><a target="_blank" class="showbtn" showtry="1" href="/tryrun/showphp/demo_constant2">尝试一下 »</a>
                        </div><p><b>提示：</b>使用 PHP 的时候，注意常量与<a href="https://www.w3cschool.cn/php/php-variables.html" target="_blank" style="background-color: rgb(255, 255, 255);">变量</a>的区别。</p></div>
                    <div style="clear:both"></div>
                </div>
                <!--我要赞赏-->
                <div class="project-sq"></div>
                <!--我要赞赏结束-->
                <div class="content-links">
                    <div class="previous-link">← <a data-id="php-datatypes" title="上一篇：PHP 5 数据类型">PHP 5 数据类型</a></div>
                    <div class="next-link"><a data-id="php-string" title="下一篇：PHP 字符串变量">PHP 字符串变量</a> →</div>
                </div>
                <!--练习、出题、写笔记-->
                <div class="project-operation">
                    <div class="pull-right">
                        <a href="javascript:;" target="_blank" class="op-btn note-btn" onclick="openNote()"><i class="icon-pencil"></i>写笔记</a>
                    </div>
                </div>
                <!--横版广告放置-->
                <div class="abox-item"><div class="abox-content"><a href="https://www.w3cschool.cn/minicourse/" target="_blank"><img src="/attachments/image/20171102/1509617445739290.png" alt="W3Cschool app 编程微课功能上线" /></a>     </div></div></div>
            <div class="navigation-box">
                <a data-id="php-datatypes" title="上一篇：PHP 5 数据类型" class="navigation navigation-prev"><i class="icon-chevron-left"></i></a>
                <a data-id="php-string" title="下一篇：PHP 字符串变量" class="navigation navigation-next"><i class="icon-chevron-right"></i></a>
            </div>
        </div>
        <div id="pro-footer">
            <div class="s-footer">
                <div class="s-footer-bottom">
                    <p>Copyright &copy; 2018 <a href="//www.w3cschool.cn" title="w3cschool">w3cschool.cn </a> All Rights Reserved. </p>
                </div>
            </div>
        </div>
    </div>
</div>
<div class="bottom-tools" style="bottom: 40px;">
    <a id="scrollUp" href="javascript:;" title="飞回顶部"></a>
    <a class="onlinenote" style="display: none;" title="在线笔记" href="javascript:;" data-module="page">在线笔记</a>
    <div class="qr-tool">二维码</div>
    <a id="feedback" class="webjy" title="建议反馈" href="javascript:;" data-module="page" onclick="showDialogBox(this)">建议反馈</a>
    <div class="qr-img"><img src="//7nsts.w3cschool.cn/images/w3c/w3cschool.jpg" alt="二维码"></div>
</div>

<div class="feedback-Box" style="display: none;">
    <div class="feedback-Box-content" style="width: 800px;">
        <div class="feedback-Box-top">
            <span class="feedback-Box-title">意见反馈</span>
            <span onclick="closeDialogBox(this)" class="feedback-Box-close">X</span>
        </div>
        <ul>
            <li class="feedback-box" >
                <div id="feedbackRadio" type="radio" name="feedbackType" data-value="0" style=""> 意见反馈：</div>
                <textarea  name="reportInfo" id="elmaaa" class="feedback-text" rows="15" placeholder="请留下您宝贵的意见反馈吧。" style="width: 700px;height:200px;overflow:auto;" ></textarea>
                <p>联系方式：</p>
                <input type="text" placeholder="留个联系方式呗..." name="reportAddress" class="radio-text" id="reportAddress" style="height: 30px;width: 200px;">
            </li>
        </ul>
        <button class="search-s" onclick="dialogSubmit(this)" id="reportSubmit">提交</button>
    </div>
</div>

<div id="note-start" style="display: none"></div>

<div id="detail" style="display:none;">
    <div id="note-Dialog" class="note-Dialog" >
        <div class="note-Box-content" >
            <div class="ntitlebox">
                <input type="text" placeholder="" name="ntitle" class="ntitle" id="ntitle" >
            </div>
            <div id="editorarea">
                <textarea  name="ncontent" id="ncontent" class="ncontent" rows="15" placeholder="" style="width: 700px;height:200px;overflow:auto;" ></textarea>
            </div>
            <p></p>
            <a class="closenote" href="/my/note" target="_blank" >查看完整版笔记</a>
            <button class="notesubmit"  id="notesubmit">保存</button>
            <button class="notebtn pull-right closenote" style="margin:20px 0" >关闭</button>
        </div>
    </div>
</div>

<div class="report-Box" style="display: none;">
    <div class="report-Box-content">
        <div class="report-Box-top">
            <span class="report-Box-title">违规举报</span>
            <span onclick="closeReportBox(this)" class="report-Box-close">X</span>
        </div>
        <ul>
            <li class="radio-box">
                <input id="reportRadio" type="radio" name="reportType" value="1" checked="checked" /> 广告等垃圾信息
            </li>
            <li class="radio-box">
                <input id="reportRadio" type="radio" name="reportType" value="2" /> 不友善内容
            </li>
            <li class="radio-box">
                <input id="reportRadio" type="radio" name="reportType" value="3" /> 违反法律法规的内容
            </li>
            <li class="radio-box">
                <input id="reportRadio" type="radio" name="reportType" value="4" /> 不宜公开讨论的政治内容
            </li>
            <li class="radio-box" onclick="reportOther(this)">
                <input id="reportRadio" type="radio" name="reportType" value="0" /> 其他
                <input type="text" class="radio-text" name="reportInfo" value="" placeholder="请填写您的举报理由。">
            </li>
        </ul>
        <button class="search-s" onclick="reportSubmit(this)" id="reportSubmit">提交</button>
    </div>
</div>
<div id="tryframebox" class="tryframebox" >
    <div id="tryClose" >关闭</div>
    <div id="tryNewWin"  class="winshowtry">新窗口</div>
    <iframe id="tryframe" class="tryframebox" name="tryframe"  ></iframe>
</div>

<!-- 加载css3 loading div -->
<div class="loading-css3">
    <div class="spinner">
        <div class="spinner-container container1">
            <div class="circle1"></div>
            <div class="circle2"></div>
            <div class="circle3"></div>
            <div class="circle4"></div>
        </div>
        <div class="spinner-container container2">
            <div class="circle1"></div>
            <div class="circle2"></div>
            <div class="circle3"></div>
            <div class="circle4"></div>
        </div>
        <div class="spinner-container container3">
            <div class="circle1"></div>
            <div class="circle2"></div>
            <div class="circle3"></div>
            <div class="circle4"></div>
        </div>
    </div>
</div>
<div class="widget-body" data-type="project"></div>
<div class="pay-area" data-static="//www.w3cschool.cn/statics"></div>
<div class="dialog-area"></div>
<script src="//www.w3cschool.cn/plugins/ueditor/third-party/SyntaxHighlighter/shCore.min.js" type="text/javascript"></script>
<script src="//www.w3cschool.cn/statics/js/commonfooter.js" type="text/javascript"></script>
<script src="//www.w3cschool.cn/statics/js/clipboard.js" type="text/javascript"></script>
<script src="//www.w3cschool.cn/statics/js/project.view.js" type="text/javascript"></script>
<script src="//www.w3cschool.cn/statics/core/ajaxdo.core.js" type="text/javascript"></script>
<script src="//www.w3cschool.cn/statics/js/paypraise.js" type="text/javascript"></script>
<script src="//www.w3cschool.cn/statics/js/base64.js" type="text/javascript"></script>
<script>
    var kn = {
        kename:'php-constants',
        pename:'php',
        ismenu:'0',
        fid:'15472',
        ktitle:'PHP 5 常量',
        ktype:'kn',
        original:'1',
        uid:'222748',
        tryurl:'',
        flags:'rich',
        codenote:'',
        copybtn:'<a class="code-copy" title="复制到剪切板"><i class="icon-copy"></i></a><a class="code-try" title="编辑代码"><i class="icon-edit"></i></a>',
        copybtn2:'<a class="code-copy right0" title="复制到剪切板"><i class="icon-copy"></i></a>',
        tryhtml:'<button class="btn btn-info dshowtry">尝试一下</button><div class="coderes"></div>',
        tryhtml2:'<button class="btn btn-info dshowtry">尝试一下</button>',
    };
    var book = {
        pename:'php',
    };
    var UserInfo =  {
        tipexp:'1',
        uid: '222748',
    };

    var Gvar = {
        activityflag: '0',
        remoteLangs: ['php','ruby','go','python','python3','c','cpp','perl','perl6','java','lua'],
        supportLangs: ['php','ruby','go','python','python3','c','cpp','perl','perl6','java','lua', 'html', 'js', 'javascript'],
    };
    function openNote(){
        $(".onlinenote").trigger("click");
    }
</script>
<script src="//www.w3cschool.cn/statics/js/work_view_ajax.js" type="text/javascript"></script>
</body>
</html>